The Bagan Marathon, Myanmar

Who: 75 runners

When: November 15, 2014 and 2015

Why it's unique: There are no less than 2,000, centuries-old Buddhist temples and pagodas dotting the steep turf of this run though Myanmar's historical, archaeological zone outside Yangon. The race starts and finishes at the famed Htilominlo Temple, and takes place on a tricky topographic mix of sand, dirt, and paved roads in blistering temps that reach about 90-degrees Fahrenheit. [bagan-temple-marathon.com]